1960

6.9

1956

6.5

2007

6.7

2000

7.3

1996

6.6

1996

6.3

1998

5.3

1991

6.1

2008

6.4

1995

6.6

1997

6.4

1957

7.6

1982

6.7

2002

5.7

1959

7.7

2003

6.0

2007

6.0

2006

6.4

1976

7.8

1994

7.3